Diet Feeding Research Articles

Comparative analysis of the biochemical composition of rainbow trout blood serum under different feeding diets

Rational and efficient feeding of aquaculture objects is one of the foundations of production in highly productive fish farming. The aim of the study was to compare the composition of production compound feeds for aquaculture objects and to study the effect of compound feeds on the biochemical parameters of the blood serum of rainbow trout. To achieve the aim of the study, 10 groups of rainbow trout (Parasalmo mykiss (Walbaum, 1792) of the "Rofor" breed) grown in production conditions of cage farms in Karelia were selected. Alanine transferase, aspartate aminotransferase, alkaline phosphatase, total protein, albumins, creatinine, urea, glucose, total bilirubin and total cholesterol were determined in the blood serum of the studied individuals. The obtained result has an important practical significance since with excessive intake of carbohydrates these fish develop liver glycogen overload syndrome due to insufficient insulin production. Therefore, the optimal carbohydrate content for them is 20-30%, including 5-6% fiber. In this case, monosaccharides are used better - glucose, fructose, mannose, somewhat worse - disaccharides and starch, and cellulose is broken down only by 10-20% of the consumed. In addition, it is necessary to take into account that trout, as a cold-loving fish, cannot use carbohydrates in the same volume as heat-loving objects of aquaculture, therefore, in order to save protein, which can be used for energy purposes, it is necessary to additionally introduce fats into their diets. However, in the studied compound feeds this component did not meet the GOST standards. The results of the conducted research can be used to optimize the composition of production feed for rainbow trout and to register background ichthyohematological criteria for the quality of keeping highly productive aquaculture species.

The Influence of Different Dietary Categories on Life-History of Daphnia pulex

The type and amount of food that Cladocera species eat is known to affect their growth, development, capacity for reproduction, and ultimately the size of their populations. This study examines the influence of different diet types and mixtures on the Daphnia pulex (Leydig, 1860) life-history characteristics such as development, growth, and reproduction in a lab setting. D. pulex was fed with a yeast diet (Saccharomyces cerevisiae), a fresh green algal diet (Scenedesmus acutus), an aquarium fish feed diet (Arthrospira platensis), and a mixture diet (yeast, algae and fish feed) in a controlled static experiment for 21 days in the study. When D. pulex was fed with only one type of food, body weight, body size, somatic, and population growth rates decreased compared to the mixed diet but continued to increase compared to the control group throughout the 21-day experimental duration (P≤0.05). In contrast, according to morphometric measurements, the effect of a diet containing only cyanobacteria caused a stagnation in growth rates, while growth rates increased in those fed with cyanobacteria-containing feeds added to the mixed diet (P≤0.05). Our results show that the type of food and its mixtures significantly affect the vital characteristics of the D. pulex population.

Medial hypothalamic MC3R signalling regulates energy rheostasis in adult mice.

Although mammals resist both acute weight loss and weight gain, the neural circuitry mediating bi-directional defense against weight change is incompletely understood. Global constitutive deletion of the melanocortin-3-receptor (MC3R) impairs the behavioural response to both anorexic and orexigenic stimuli, with MC3R knockout mice demonstrating increased weight gain following anabolic challenges and increased weight loss following anorexic challenges (i.e. impaired energy rheostasis). However, the brain regions mediating this phenotype are not well understood. Here, we utilized MC3R floxed mice and viral injections of Cre-recombinase to selectively delete MC3R from the medial hypothalamus (MH) in adult mice. Behavioural assays were performed on these animals to test the role of MC3R in MH in the acute response to orexigenic and anorexic challenges. Complementary chemogenetic approaches were used in MC3R-Cre mice to localize and characterize the specific medial hypothalamic brain regions mediating the role of MC3R in energy homeostasis. Finally, we performed RNAscope in situ hybridization to map changes in the mRNA expression of MC3R, pro-opiomelanocortin and agouti-related peptide following energy rheostatic challenges, as well as to characterize the MC3R expressing cells in dorsal MH. Our results demonstrate that MC3R deletion in MH increases feeding and weight gain following high-fat diet feeding, and enhances the anorexic effects of semaglutide, in a sexually dimorphic manner. Furthermore, although the arcuate nucleus exerts an important role in MC3R-mediated effects on energy homeostasis, viral deletion in the dorsal MH also resulted in altered energy rheostasis, indicating that brain regions outside of the arcuate nucleus also contribute to the role of MC3R in energy rheostasis. Together, these results demonstrate that MC3R-mediated effects on energy rheostasis result from the loss of MC3R signalling in medial hypothalamic neurons and suggest an important role for dorsal-MH MC3R signalling in energy rheostasis. KEY POINTS: Melanocortin-3-receptor (MC3R) signalling regulates energy rheostasis in adult mice. Medial hypothalamus regulates energy rheostasis in adult mice. Energy rheostatic stimuli alter mRNA levels of agouti-related peptide, pro-opiomelanocortin and MC3R. Dorsal-medial hypothalamus (DMH) MC3R neurons increase locomotion and energy expenditure. MC3R cell types in DMH are sexually dimorphic.

Effects of diet and ovariectomy on Toxoplasma gondii brain infection: functional alterations and neuronal loss in rats.

Epidemiological evidence associates Toxoplasma gondii latent infection with the development of neuropsychiatric disorders, and various immunological and environmental factors play key pathophysiological roles through host immune response alterations. We investigated the cognitive and motor alterations occurring in the terminal stage of T. gondii infection in rats, and whether a low-protein diet, a high-fat diet or ovariectomy may accelerate their development, given the role of malnutrition and menopause on immunity and resistance to infection. In two sets of experiments, 2-month-old (157.5 ± 4.3 g, n = 42) male (n = 18) and female (n = 24) Wistar rats were infected with T. gondii (ATCC 40050). Open-field and elevated plus maze tests were performed in the terminal stage of infection first and then in the early stage in low-protein diet-fed, high-fat diet-fed and ovariectomized infected rats. Late-stage (90 days) infected and early-stage (17 days) low-protein diet-fed groups showed significant decreases in body weight (42.42%↓, P = 0.016 and 57.14%↓, P < 0.001 versus non-infected, respectively), increases in body temperature (P = 0.001 and P < 0.001, respectively), decreases in blood glucose levels (P = 0.006 and P = 0.020, respectively), signs of cognitive and motor impairment and lower neuron counts. The alterations observed in high-fat diet-fed and ovariectomized infected animals were milder. Low-protein diet feeding to T. gondii-infected rats accelerated the occurrence of the infection terminal stage. Thus, a diet low in proteins could transform a slow early-stage T. gondii infection into an active neurotoxoplasmosis with neuropsychiatric manifestations and possible neurodegeneration in rats.

Time restricted feeding with or without ketosis influences metabolism-related gene expression in a tissue-specific manner in aged rats.

Many of the 'hallmarks of aging' involve alterations in cellular and organismal metabolism. One pathway with the potential to impact several traditional markers of impaired function with aging is the PI3K/AKT metabolic pathway. Regulation of this pathway includes many aspects of cellular function, including protein synthesis, proliferation and survival, as well as many downstream targets, including mTOR and FOXOs. Importantly, this pathway is pivotal to the function of every organ system in the human body. Thus, we investigated the expression of several genes along this pathway in multiple organs, including the brain, liver and skeletal muscle, in aged subjects that had been on different experimental diets to regulate metabolic function since mid-life. Specifically, rats were fed a control ad lib diet (AL), a time restricted feeding diet (cTRF), or a time restricted feeding diet with ketogenic macronutrients (kTRF) for the majority of their adult lives (from 8-25 months). We previously reported that regardless of macronutrient ratio, TRF-fed rats in both macronutrient groups required significantly less training to acquire a biconditional association task than their ad lib fed counterparts. The current experiments expand on this work by quantifying metabolism-related gene expression across tissues and interrogating for potential relationships with cognitive performance. AKT expression was significantly reduced in kTRF fed rats within liver and muscle tissue. However, AKT expression within the perirhinal cortex (PER) was higher in kTRF rats with the best cognitive performance. Within CA3, higher levels of FOXO1 gene expression correlated with poorer cognitive performance in ad libitum fed rats. Together, these data demonstrate diet- and tissue-specific alterations in metabolism-related gene expression and their correlation with cognitive status.

Effects of stocking density on growth performance, digestive enzyme activity, biochemical composition, and economic efficiency of a new strain of Oreochromis niloticus reared in cage culture system at Sindh Pakistan.

The latest strain of Oreochromis niloticus is an altered ecological adaptation for sustainable aquaculture and is necessary to sustain stocking density and reduce physiological stress of the new strain. The present study aimed to determine the optimum stocking density, biological performance, and economic efficiency of the Nile tilapia. The 14,000 healthy seeds and uniform weight (40 ± 2.4 g) sex-reversed Oreochromis niloticus were stocked in four cages, which are cage (1) 20 fish/m3, cage (2) 30 fish/m3, cage (3) 40 fish/m3, and cage (4) 50 fish/m3. The fish were fed 30% dietary protein and feeding frequency three times per day and the feeding rate adjusted according to the fish body weight. Results showed a significantly higher growth, weight gain, and specific growth rate in Nile tilapia stocking density on cage (1), 20 fish/m3 and cage (2), 30 fish/m3 compared to cage (3), 40 fish/m3 and cage (4), 50 fish/m3 (p < .05). The survival and growth rate showed an inverse relationship with stocking density. The feed conversion ratio (FCR) is the lowest in cage (1) and cage (2), which is significantly different from those of other cages (p < .05). The profit index (%) was significantly higher at low density. There was no significant variation in the HSI, VSI and CF. The digestive enzymes such as lipase and amylase were secreted highly in the cages (3) and (4) but high protease was secreted in cage (1). The lipid, ash, and protein of the whole fish were reduced to a lower density, but the moisture levels in the fish bodies raised significantly (p < .05) with increasing stocking density. The phenomenal regression indicates that 25-35 fish/m3 are optimum stocking density for Nile tilapia in the cage culture system. The current study has made significant step toward optimizing the stocking density of a new strain and developing cage culture in Pakistan.

Nutritional management and autism spectrum disorder: A systematic review.

Autism spectrum disorder (ASD) presents unique challenges related to feeding and nutritional management. Children with ASD often experience feeding difficulties, including food selectivity, refusal, and gastrointestinal issues. Various interventions have been explored to address these challenges, including dietary modifications, vitamin supplementation, feeding therapy, and behavioral interventions. To provide a comprehensive overview of the current evidence on nutritional management in ASD. We examine the effectiveness of dietary interventions, vitamin supplements, feeding therapy, behavioral interventions, and mealtime practices in addressing the feeding challenges and nutritional needs of children with ASD. We systematically searched relevant literature up to June 2024, using databases such as PubMed, PsycINFO, and Scopus. Studies were included if they investigated dietary interventions, nutritional supplements, or behavioral strategies to improve feeding behaviors in children with ASD. We assessed the quality of the studies and synthesized findings on the impact of various interventions on feeding difficulties and nutritional outcomes. Data extraction focused on intervention types, study designs, participant characteristics, outcomes measured, and intervention effectiveness. The review identified 316 studies that met the inclusion criteria. The evidence indicates that while dietary interventions and nutritional supplements may offer benefits in managing specific symptoms or deficiencies, the effectiveness of these approaches varies. Feeding therapy and behavioral interventions, including gradual exposure and positive reinforcement, promise to improve food acceptance and mealtime behaviors. The findings also highlight the importance of creating supportive mealtime environments tailored to the sensory and behavioral needs of children with ASD. Nutritional management for children with ASD requires a multifaceted approach that includes dietary modifications, supplementation, feeding therapy, and behavioral strategies. The review underscores the need for personalized interventions and further research to refine treatment protocols and improve outcomes. Collaborative efforts among healthcare providers, educators, and families are essential to optimize this population's nutritional health and feeding practices. Enhancing our understanding of intervention sustainability and long-term outcomes is essential for optimizing care and improving the quality of life for children with ASD and their families.

Effects of Sugar in Adult Diet on the Development and Reproduction of Spodoptera frugiperda (J. E. Smith) under Laboratory Conditions in Burkina Faso

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is the pest causing enormous economic losses to Maize production. To date, there is little documentation on rearing protocols for S. frugiperda. This study aimed to evaluate the effect of honey and glucose as a nutrient source on the developmental parameters and reproduction of S. frugiperda under laboratory conditions. In this work, we compared the larval period, larval survival, pupal period, pupal survival, adult longevity, female oviposition period, female fecundity and egg hatching of S. frugiperda adults under three feed diets: distilled water (D1), 10% bee honey with water solution (D2) and 10% glucose with water (D3). The longest larval period and highest larval survival were achieved on D3. The longest longevity, oviposition and post-oviposition periods, the highest fecundity and number of eggs per female per day were observed on D3. The diet D3 had significant effects on live cycle of S. frugiperda parameters compared with D1 and D2. Our results will enable us to improve mass rearing of S. frugiperda in laboratory.

Deleterious Effects of Yoyo Dieting and Resistant Starch on Gastrointestinal Morphology.

Obesity is associated with structural deterioration in the gut. Yoyo dieting, which refers to repeated phases of dieting and non-dieting periods leading to cyclic weight loss and regain, is a common occurrence in individuals with obesity. However, there is limited evidence on how gut structures are affected in yoyo dieting. There is good evidence suggesting that increased intake of resistant starch (RS) may be beneficial in promoting structural improvements in the gut. This investigation aimed to explore the effect of yoyo dieting on gastrointestinal structure and whether RS has beneficial effects in improving obesity-related gastrointestinal damage. In this study, male and female C57BL/6 mice were assigned to six different diets for 20 weeks: (1) control diet, (2) high fat diet (HF), (3) yoyo diet (alternating HF and control diets every 5 weeks), (4) control diet with RS, (5) HF with RS, and (6) yoyo diet with RS. Distal colon was collected for epithelial barrier integrity measurement. The small and large intestines were collected for histological assessment. After 20 weeks, yoyo dieting resulted in increased colonic inflammation and exacerbated mucosal damage in comparison with continuous HF diet feeding. RS supplemented in HF and yoyo diets reduced mucosal damage in comparison to diets without RS. However, RS supplementation in a control diet significantly increased inflammation, crypt length, and goblet cell density. There were no significant differences in epithelial change and epithelial barrier integrity across diet groups. This study suggests that yoyo dieting worsens gut damage, and incorporating high levels of RS may be detrimental in the absence of dietary challenge.

Tyrosine Hydroxylase Is Required for the Larval-Pupal Transformation and Immunity of Plutella xylostella: Potential for Pest Management.

Plutella xylostella has developed high levels of resistance to many commonly used insecticides. Tyrosine hydroxylase (TH) is essential for insect survival; thus, we evaluated whether TH could be a potential target for controlling P. xylostella. In this study, PxTH was identified; further qPCR analysis showed that PxTH increased its expression during larval pupation and was highly expressed in the head and epidermis of prepupa in P. xylostella. Subsequently, we found a significant decrease in insect pupation and eclosion rates after injection of dsPxTH or a feeding diet supplemented with 3-iodo-tyrosine (3-IT) as a TH inhibitor in P. xylostella. Moreover, this study suggested that PxTH enzyme activity and dopamine concentrations were significantly decreased, agreeing with the blockage of larval-pupal cuticle tanning, with thinner puparium and less melanization after feeding 3-IT. In addition, expression levels of four antimicrobial peptide genes were significantly inhibited after P. xylostella feeding with 3-IT, and injection of Escherichia coli resulted in 73.3% mortality, indicating that PxTH was required for immune responses. In summary, these results confirmed that PxTH was involved in the development and immunity of P. xylostella, suggesting a critical potential novel insecticide target for RNAi-based pest control.

Single-cell protein (SCP) meals from Methylovorus menthalis as feed ingredients for freshwater Atlantic salmon (Salmo salar L.): Digestibility, growth performance, nutrient utilization, and fish health

This study provides nutritional evaluations of single-cell protein (SCP) meals produced from a naturally-occurring methylotrophic microorganism (Methylovorus menthalis) in feeds for freshwater-phase Atlantic salmon (Salmo salar L., <30 g initial weight). Three trials were conducted (in triplicate) to: 1. determine ‘single-ingredient’ apparent digestibility coefficients (ADCs) in an 80:20 ingredient substitution digestion assay (Trial 1), 2. examine effects of partial (50 %) or complete (100 %) substitution of major plant-protein ingredients on feed consumption (a proxy for palatability) and digestibility using nutritionally-balanced test diets (Trial 2), and 3. evaluate effects of graded inclusion levels (up to 30 %) at partial or complete substitution of marine and plant-based ingredients on growth performance, nutrient utilization, and fish health (Trial 3). In Trial 1, dry matter (DM), crude protein (CP), gross energy (GE), and essential amino acids (EAAs) in M. menthalis SCP meal were highly digestible at 85, 92, 88, and 86–96 %, respectively. In Trial 2, feed consumption of nutritionally-balanced diets were unaffected by up to 26 % M. menthalis SCP meal inclusion (100 % substitution of major plant-proteins), but compared to the control diet showed higher ADCs for DM, GE, and methionine, the same ADC for tryptophan, and with only minor reductions in ADCs for CP and other EAAs. For Trial 3, inclusion of up to 30 % M. menthalis SCP meal did not impact fork length, Fulton's condition factor, survival, haematocrit, packed red blood cell counts, viscerosomatic index, feed conversion ratio, or protein efficiency ratio, however apparent feed intake, protein intake, final body weight, weight gain, and specific growth rate decreased, most notably at levels exceeding 10–20 % of the diet. Feed consumption (and nutrient/energy intakes) by fish fed increasing dietary SCP meal levels was linearly suppressed and had a cascading effect in reducing whole-body protein, lipid, and energy gains. However, this was not reflected in their corresponding apparent net retention efficiencies for protein, lipid, or energy, where no differences were observed at any SCP meal inclusion level, suggesting a possible ‘correctable’ diet palatability issue at high inclusion levels. Feeding diets with up to 30 % M. menthalis SCP meal had no impacts on plasma analyte biochemistry or intestinal histopathology. Collectively, results demonstrate that SCP meals derived from a naturally-occurring methylotrophic microorganism (M. menthalis) produced under scalable aerobic fermentation can be effectively included in Atlantic salmon pre-smolt feeds at 10–20 % at substitution of conventional marine and plant-protein ingredients with minimal or no effects on feed intake, nutrient digestibility, production performance, whole-body composition, nutrient utilization, intestinal histopathology, and fish health.

Modulation of the Plasma Lipidomic Profile in Piglets Fed Polar Lipid-Rich Diets.

Background: Polar lipids from dairy are novel sources of energy that may replace other dietary lipids and impact plasma lipidomic profiles in piglets. This study evaluated the impact of feeding diets rich in polar lipids on the plasma lipidome of piglets during the weaning period. Material and Methods: Weaned male piglets (n = 240; 21 days of age; 6.3 ± 0.5 kg of BW) were blocked by initial weight and distributed into 48 pens of five animals each in a complete randomized block design with a 2 × 3 factorial arrangement of treatments as follows: a plant-based diet rich in neutral lipids from soybeans (24 pens; SD) or a polar lipid-rich diet by-product of cheese making (24 pens; PD) from weaning until the 21st day of the nursery phase. Within each diet group, animals received one of three milk replacers (MR; 0.5 L/d/animal) for the first 7 days after weaning: (1) commercial MR containing animal and coconut lipids (CO); (2) polar lipid-based MR (PO); or (3) soybean lipids-based MR (SO). Results: The PD diet group increased the plasma concentrations of sphingolipids, phospholipids, and cholesterol esters, but did not impact the concentrations of glycerolipids (GLs). Both the PO and CO milk replacers increased the plasma concentrations of ceramide, acyl-chain phosphatidyl choline, and cholesterol esters. The plasma concentrations of GLs containing 18-carbon fatty acids such as 18:0, 18:1, 18:2, and 18:3, were higher in SD, whereas GLs containing 16:0 and 20:3 were higher in PD. Conclusions: In summary, the diet lipid type significantly modulated the plasma lipid composition in piglets 7 days after weaning. The dietary inclusion of polar lipids in diets for growing pigs can modulate the plasma lipidomic profile, relative to plant-based diets rich in soybean lipids. Cost may be a major consideration when using these lipids in pig diets. Their health benefits need to be further characterized in other models of stress and inflammation.

Accuracy and precision of diets fed to close-up cows on dairy farms and its association with early lactation performance

Ensuring a consistent ration is critical for maximizing lactating cow performance, but this is not known for dry cows. The objectives of this cohort observational study were to: 1) characterize close-up dry cow diets fed on commercial farms in Ontario, Canada, 2) describe the accuracy of the nutrient composition between the formulated close-up diet and the diet offered to the cows, 3) describe the precision of the close-up diets across time, and 4) explore potential associations of that accuracy and precision with blood metabolic parameters and milk yield of cows in early lactation. Forty free-stall dairy farms were visited once every 4 wk, for a total of 6 visits to each farm, from April to October 2022. At each visit, samples of the close-up diet were collected and analyzed for dry matter (DM) content and chemical composition. Close-up diet formulations were also obtained by each farm's nutritionists. During each visit, fresh cows (0 to 14 d in milk [DIM]) had blood samples taken for blood metabolites. The same cows were also monitored for milk yield up to 120 DIM. Multivariable models were used to analyze associations between variability (in relation to the formulated diet and across time) of nutrients in the close-up diet, as measured by coefficient of variation (CV), and outcomes in fresh cows. Corn silage (67.6% of farms) and straw (24.3% of farms) were the predominant primary forage sources used in the close-up dry cow diets. Soybean meal (37.8% of farms) and canola meal (18.9% of farms) were the main ingredients used as primary concentrate sources. Overall, the diets offered did not accurately represent the formulated diets. With the exception of net energy for lactation (NEL), the CVs for the other nutrients were all greater than 5%. Diet variability, both between fed and formulated diets and from visit to visit during the close-up period, was associated with metabolic markers and dairy cow production. Lower variability in non-fiber carbohydrates (NFC) between the fed and formulated diets was associated with better liver health index scores. Visit-to-visit variability in fat% and NFC% were associated with blood β-hydroxybutyrate (BHB) concentrations, while NFC% variability was associated with blood glucose levels. Serum nonesterified fatty acids (NEFA) concentrations were associated with visit-to-visit variability in DM% and CP%. These results underscore the importance of maintaining consistency between diet formulations and feeding practices over time to optimize early-lactation dairy herd performance and health, granted that these diets are correctly formulated to meet the nutritional needs of cows in the close-up period and applied with recommended feeding practices.

Anthelmintic Treatment Reveals Sex-Dependent Worm-Gut Microbiota Interactions.

Gastrointestinal helminths interact with the gut microbiota in ways that shape microbiota structure and function, but these effects are highly inconsistent across studies. One factor that may help explain variation in parasite-microbiota interactions is host sex since helminths can induce sex-specific changes in feeding behaviour and diet that might cascade to shape gut microbial communities. We tested this idea using an anthelmintic treatment experiment in wild Grant's gazelles (Nanger granti). We found that in males, anthelmintic treatment induced short-term shifts in microbial diversity and structure within ~40-70 days, but in females, treatment had effects on microbiota structure that emerged over a longer period of ~500 days. Long-term effects of treatment on the microbiota of females were potentially due to sex-specific changes in feeding behaviour since deworming nearly doubled the time females spent feeding, but did not affect feeding time in males. In support of this idea, anthelmintic treatment eliminated associations between microbial diversity and diet in females, and treated females maintained a more stable abundance of microbial taxa and predicted functions. Together, these findings suggest that accounting for host traits can help uncover mechanisms, such as changes in diet, by which helminths interact with the microbiota.

Nesfatin-1 is involved in hyperbaric oxygen-mediated therapeutic effects in high fat diet-induced hyperphagia in mice.

Obesity is a worldwide health issue. Effective and safe methods for obesity management are highly desirable. In the current study, hyperbaric oxygen (HBO) treatment was investigated as a potential treatment against obesity-associated hyperphagia and hyperenergy intake. Diet induced obesity (DIO) mice model was established with high fat diet (HFD) feeding, HBO was then co-administered. Food and energy intake were assessed with nocturnal food intake assay. Immunohistochemistry for c-Fos was performed for neuronal activation in arcuate nucleus (ARC), paraventricular nucleus of hypothalamus (PVN) and lateral parabrachial nucleus (LPBN) of brain. Additionally, enzyme-linked immunosorbent assay (ELISA) in serum and immunofluorescence in LPBN were performed. Results indicated that HBO co-treatment effectively decreased food and energy intake in DIO mice, reverted the abnormal neuronal activation in the ARC and PVN, and enhanced both peripheral and central nesfatin-1 peptide levels without affecting serum leptin levels. While SHU9119 microinjection in LPBN effectively abolished the beneficial effects of HBO on body weight, visceral fat, nocturnal feeding and energy intake in DIO mice. In conclusion, HBO treatment could effectively protect against HFD-induced increase of food and energy intake, which is associated with its central effects against abnormal neuronal activation in ARC and PVN and enhanced peptide levels of nesfatin-1 both centrally and peripherally. The melanocortin system downstream of nesfatin-1 may exert a potential effect in this process.

Simultaneous treatment with palm-LEAP2(1-14) and feeding high-fat diet attenuates liver lipid metabolism but not obesity: Sign of selective resistance to palm-LEAP2(1-14).

Liver-enriched antimicrobial peptide 2 (LEAP2) is a natural antagonist/inverse agonist of ghrelin receptor GHSR. Its truncated palmitoylated analog palm-LEAP2(1-14) promised anti-obesity properties because it exhibited favourable stability and an acute anorexigenic effect in our previous studies. Here we demonstrate desirable palm-LEAP2(1-14) pharmacokinetics, with significant levels of the peptide persisting in mouse blood 3 hours after its subcutaneous administration. Palm-LEAP2(1-14) reduced ghrelin-induced c-Fos immunoreactivity in arcuate nucleus and area postrema, in line with previously described silencing of ghrelin orexigenic effect. In spite of this, anti-obesity effect was not reached by two-week palm-LEAP2(1-14) treatment in mice with diet-induced obesity. Similarly, palm-LEAP2(1-14) administered simultaneously with high-fat diet feeding for 8 weeks did not protect mice from development of obesity and related biochemical changes. However, palm-LEAP2(1-14) kept its ability to attenuate liver de novo lipogenesis, and prominently lowered liver gene expression of nuclear receptors PPARG, SREBF1 and PPARA, and also expression of lipogenic and lipolytic enzymes. In our recent study, we described a high-fat diet-induced ghrelin resistance, reversible by switch to standard diet, followed by resistance to the acute anorexigenic effects of palm-LEAP2(1-14). Here we conclude that this resistance to palm-LEAP2(1-14) in obesity is probably selective and does not concern its ability to inhibit liver lipid metabolism.

Dietary feeding techniques for body weight control in horses with equine metabolic syndrome

Dietary feeding techniques for body weight control in horses with equine metabolic syndrome

Modeling and Evaluation of Murine Diabetic Cardiomyopathy Model.

The underlying pathophysiological mechanisms of diabetic cardiomyopathy (DbCM), a leading cause of mortality among patients with type 2 diabetes mellitus (T2DM), remain poorly understood. The myocardial toxicity associated with T2DM is attributed to factors such as lipotoxicity, glucotoxicity, oxidative stress, reduced cardiac efficiency, and lipoapoptosis. Compared to rats, mice offer greater accessibility, cost-effectiveness, and broader applicability for animal experiments. Insulin resistance and impaired insulin secretion are crucial factors in the pathophysiology of T2DM. We introduce a novel nongenetic murine model that replicates the progression of human DbCM induced by a combination of high-fat diet (HFD) feeding and streptozotocin (STZ) injection. In this study, we used wild-type C57BL/6J mice, administering an HFD regimen for 12 weeks, followed by intraperitoneal injections of STZ for an additional 12 weeks to induce characteristic manifestations of T2DM. We conducted oral glucose tolerance tests and measured serum insulin concentrations to confirm the development of insulin resistance and insufficient insulin secretion. Cardiac structure and function were rigorously assessed through noninvasive transthoracic echocardiography. Pathological characteristics were evaluated through Masson's trichrome staining and wheat germ agglutinin (WGA) staining, revealing pathological features related to DbCM. Therefore, we provide a robust and versatile method for establishing a nongenetic murine model of DbCM.

Protective Effects of the Food Supplement Flexovital in a Model of Cardiovascular-Kidney-Metabolic Syndrome in Mice.

Background/Objectives: The prevalence of cardiovascular-kidney-metabolic (CKM) syndrome is increasing rapidly, and cardiovascular complications pose significant risks in individuals with kidney disease and metabolic dysfunction. Understanding the mechanisms of CKM disorders is crucial, as is the discovery of novel preventive treatments. This study aimed to examine the therapeutic effects of a specially formulated nitric oxide-enhancing food additive in a mouse model of CKM syndrome induced by unilateral nephrectomy (UNX) in combination with chronic Western diet (WD) feeding. Methods: C57BL/6J mice underwent UNX and were fed a WD high in salt, sugar, and fat for 12 weeks, compared to sham-operated mice on standard chow. One group of UNX+WD mice received Flexovital (FLX), a food additive containing extracts of Rhodiola rosea and beetroot, and the amino acids L-arginine and L-citrulline. CKM parameters were assessed both in vivo and ex vivo alongside histological and biochemical analyses. Results: The UNX+WD mice showed an increase in body fat mass, the fat/lean mass ratio, and adipocyte area, of which most were significantly reduced by FLX. Elevated fasting glucose levels were also reduced by FLX, which tended towards improving glucose clearance. Elevated arterial blood pressure and endothelial dysfunction in UNX+WD mice were significantly reduced by FLX. FLX improved GFR and reduced glomerular and tubular injuries in UNX+WD mice. Additionally, FLX increased the P/O ratios of oxidative phosphorylation in the isolated renal mitochondria of UNX+WD mice. Conclusions: In this model of CKM syndrome, FLX effectively prevented the onset and progression of CKM dysfunctions induced by UNX+WD, as well as the associated organ injuries. These promising results highlight the need for validation in upcoming human trials.

Donepezil improves skeletal muscle insulin resistance in obese mice via the AMPK/FGF21-mediated suppression of inflammation and ferroptosis.

Donepezil has traditionally been used in Alzheimer's disease treatment and is known for its ability to alleviate neural inflammation and apoptosis. However, its impact on insulin signaling remains unexplored. This study sought to elucidate the novel role of donepezil in mitigating skeletal muscle insulin resistance under hyperlipidemic conditions. Western blot analysis was used to assess the expression of various proteins of interest, whereas a glucose uptake assay was performed in skeletal muscle cells via commercially available kits. An in vitro model of obesity was developed using palmitate. These in vitro findings were corroborated in vivo via insulin resistance models established through high-fat diet (HFD) feeding in mice. Intraperitoneal glucose tolerance tests and insulin tolerance tests were performed on the experimental mice. The results revealed that donepezil treatment improved insulin signaling and inflammation in palmitate-treated C2C12 myocytes and the skeletal muscle of HFD-fed mice. Notably, donepezil treatment augmented FGF21 expression and AMPK phosphorylation in the myocytes and skeletal muscle of HFD-fed mice. Knockdown of FGF21 or AMPK via siRNA reversed the effects of donepezil on insulin signaling and inflammation in cultured myocytes. We also found that donepezil ameliorated skeletal muscle insulin resistance via the FGF21-mediated suppression of ferroptosis under hyperlipidemic conditions. These findings suggest that donepezil enhances the FGF21/AMPK axis, thereby mitigating inflammation and insulin resistance in skeletal muscle. This study introduces a novel therapeutic approach for treating Alzheimer's disease patients with insulin resistance.